Which material is typically used for a lead and oakum joint?

The use of lead for a lead and oakum joint is significant due to the unique properties of lead that make it suitable for creating a watertight seal in piping systems. Lead is malleable and can be easily shaped and formed, enabling it to conform to the irregularities of the joint surfaces. When combined with oakum—a type of fiber made from hemp or jute that is traditionally used to seal joints—lead provides an effective barrier against moisture and leaks.

This combination has been widely used in plumbing and drainage systems, especially in older installations. The lead serves to fill the joint tightly alongside the oakum, which further reinforces the seal and prevents water from escaping. The inherent weight and density of lead contribute to the durability of the joint, making it resistant to the pressures and strains often found in plumbing applications.

Other materials, such as plastic, metal, and rubber, do not offer the same level of sealing capability when combined with oakum, as they lack the appropriate malleable properties or the historical context of usage that lead has established over the years in traditional plumbing practices.